Systems for detecting roadway markings (white/yellow) are nowadays based on mono or stereo cameras. The same applies to a steering assistance for the driver (lane keeping systems) based thereon. The vehicle is kept within the detected lane using a torque at the steering wheel. The series systems are characterized by high availability, but their availability may decrease in difficult situations such as backlighting, night, wetness, snow or also roadworks. The decrease in availability due to interference in the optical path and reflections on the road may also occur in stereo cameras, since there is a large, overlapping image section, and the effects occur in both camera images. One additional aspect lies in that a robust detection of the edge of the roadway is difficult to carry out when the lane is not bounded by markings but, for example, by a median strip or guard rails.
Previous systems may lead to a driver, who has become used to the system in “good situations,” for example, on freeways in Germany, becoming uncertain in the case of decreased availability, in special situations or on poor roads, and trust in the system is thus lost and the acceptance is reduced. For prevailing systems it is presently a challenge to change from a well-marked road to a poorly marked country road.
There are inventions which use a front view camera and/or a rear view camera in a vehicle in order to enable a robust lane detection system even in backlighting situations.
Publication US 20070091135c A1 discusses, for example, an approach in which a lane keeping system is also possible based on a lane detection system. In a backlighting situation it may be problematic to keep the lane only based on the detection results from images of the rear view camera, since this requires an anticipation of the lane detection, which is not ensured by the front view camera in a backlighting situation, and which cannot be ensured by the rear view camera.
Patent document DE-102006021177 A1 discusses a system which uses radar sensors as well as side and rear view cameras in order to detect a lane change of preceding vehicles. No information is provided on lane detection.